If an object is placed at a distance of 8cm from a concave mirror of focal length 10cm, discuss the nature of the image formed by drawing the ray diagram.

The boy walks towards the mirror at a speed of 1m/ s. At what speed does his image approach him?

An object is placed at a distance of 15 cm. from a convex lens of focal length 20 cm. List four characteristics (nature, position, etc.) of the image formed by the lens.

With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab the emergent ray is parallel to the incident ray.

A concave mirror and a convex lens are held separately in water. What changes, if any, do you expect in the focal length of either?

What is the unit of power of a lens? Define the unit of power of a lens.

The letter F is placed in front of a plane mirror:

1. How would its image look like when seen in a plane mirror?
2. What is the name of the phenomenon involved?

List four precautions which a student should observe while determining the focal length of a given convex lens by obtaining image of a distant object on a screen.

Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.

List two possible ways in which a concave mirror can produce a magnified image of an object placed in front of it. State the difference, if any, between these two images.